3.1 Tapirs

For the tapir collars we use the Telonics - TGW-4577-4 model, wioth data sent through the Iridium system.

They have low voltage and mortality alerts.

There are two types of location data these collars collect - regular GPS and QFP. QFP’s are Quick Fix Positions and use less battery than a standard GPS fix. Units can be configured to collect GPS, QFP, or a mix of the two location types - we collect a mix.

Our collars collect QFP’s when there is no GPS signal available.

Succeded = a successful GPS location Resolved QFP = a successful QFP location Resolved QFP = an uncertain QFP location (lower quality) Unresolved QFP = A poor quality QFP

Lets explore the implications of these different fix types for one individual - Juancito.

3.1.1 Juancito (CR)

## Reading layer `OC_trails2' from data source 
##   `/Users/runner/work/Osa-Conservation-Movement-Ecology-Lifetime-Exploration/Osa-Conservation-Movement-Ecology-Lifetime-Exploration/shapefiles/OC_trails2.shp' 
##   using driver `ESRI Shapefile'
## Simple feature collection with 204 features and 1 field
## Geometry type: MULTILINESTRING
## Dimension:     XY
## Bounding box:  xmin: -83.35712 ymin: 8.393359 xmax: -83.30851 ymax: 8.429462
## Geodetic CRS:  WGS 84

## Reading layer `shipetiari_trails' from data source 
##   `/Users/runner/work/Osa-Conservation-Movement-Ecology-Lifetime-Exploration/Osa-Conservation-Movement-Ecology-Lifetime-Exploration/shapefiles/shipetiari_trails.shp' 
##   using driver `ESRI Shapefile'
## Simple feature collection with 9 features and 15 fields
## Geometry type: LINESTRING
## Dimension:     XYZ
## Bounding box:  xmin: -71.17661 ymin: -12.50235 xmax: -71.16064 ymax: -12.47421
## z_range:       zmin: 309 zmax: 399.5
## Geodetic CRS:  WGS 84

First observation: 2022-05-29 18:01:25

Last observation: 2023-11-09 04:02:20

Active for: 528.4 days

To date we have 4011 fixes from Juancito. Of those, they are of the following types.

Var1	Freq	Percentage
Resolved QFP	2380	0.59
Resolved QFP (Uncertain)	80	0.02
Succeeded	537	0.13
Unresolved QFP	1014	0.25

Plot of the raw data:

We can then explore how these different fix types introduce error into the locations:

NOTE ZOOM IN!

So there is unreliability in all of the QFP estimates, but the GPS look great (not much spread).

Lets explore the error around each type of fix (if it has an estimate present):

Only GPS data has an error in meters (max 127m):

QFP data has error in doplar estimates:

So we have a huge spread in error. Lets subset to anything with a hdop <10,and resolved. This substantially reduced the spread but still leaves a couple of issues - notable outliers.

We should also use ctmm (as in the vultures) to find errors:

Distance moved: 2269.7 km in 528.4 days.

3.1.2 Tuva (CR)

First observation: 2023-04-14 08:01:55

Last observation: 2024-08-13 04:02:26

Active for: 486.8 days

To date we have 3173 fixes from Tuva. Of those, they are of the following types.

Var1	Freq	Percentage
Resolved QFP	1658	0.52
Resolved QFP (Uncertain)	61	0.02
Succeeded	332	0.10
Unresolved QFP	1122	0.35

Which means even less “resolved” locations.